Explosive seismic energy source with quick release valve

ABSTRACT

An apparatus for generating acoustical pulses in water by burning a fuel and air in a combustion chamber and releasing the explosive gases through an improved fast-acting valve to produce a seismic shock. A valve block opening and closing the combustion chamber with an actuator holding the valve block closed against the combustion chamber pressure by pressurized hydraulic fluid which when released allows the actuator to move away from the valve block and suddenly strike and move the valve seat block off of the combustion chamber outlet. The inertia of the actuator being larger than the valve block to provide quick opening. The hydraulic control fluid being spaced from the combustion chamber to avoid heating and fouling. Providing metal to metal seal contact means between the valve seat block and the chamber outlet and with the actuator providing an improved ignition by inserting hot compressed air at a temperature of about 750*F into the chamber and thereafter spraying fuel therein thereby eliminating the need for a spark or glow plug ignition source.

United States Patent Wood [ll] 3,750,837 Aug. 7, 1973 EXPLOSIVE SEISMIC ENERGY SOURCE WITH QUICK RELEASE VALVE Charles D. Wood, San Antonio, Tex.

[73] Assignees Southwest Research Institute, San

Antonio, Tex.

[22] Filed: Feb. 8, 1972 [21] Appl. No.: 224,522

[75] Inventor:

Primary Examiner-Benjamin A. Borchelt Assistant Examiner-H. J. Tudor Attorney-James F. Weiler, William A. Stout et al,

[ ABSTRACT An apparatus for generating acoustical pulses in water by burning a fuel and air in a combustion chamber and releasing the explosive gases through an improved fastacting valve to produce a seismic shock. A valve block opening and closing the combustion chamber with an actuator holding the valve block closed against the combustion chamber pressure by pressurized hydraulic fluid which when released allows the actuator to move away from the valve block and suddenly strike and move the valve seat block off of the combustion chamber outlet. The inertia of the actuator being larger than the valve block to provide quick opening. The hydraulic control fluid being spaced from the combustion chamber to avoid heating and fouling. Providing metal to metal seal contact means between the valve seat block and the chamber outlet and with the actuator providing an improved ignition by inserting hot compressed air at a temperature of about 750F into the chamber and thereafter spraying fuel therein thereby eliminating the need for a spark or glow plug ignition source.

8 Claims, 2 Drawing; Figures PAIENIED m "I" $750,837

sum a nr 2 EXPLOSIVE SEISMIC ENERGY SOURCE WITH QUICK RELEASE VALVE BACKGROUND OF THE INVENTION DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and particularly to The present invention relates to an explosive seismic 5 FIG. 1, the reference numeral generally indicates energy source for producing a seismic shock wave in water by burning a mixture of fuel and air in a closed combustion chamber and then releasing the gases from the explosive combustion quickly to the surrounding water. The rapid release of the explosive gases pro- 1 duces the required seismic shock.

The present invention is directed to an apparatus for providing an explosive seismic energy source having an improved quick release valve and an improved ignition of the fuel/air mixture.

SUMMARY One feature of the present invention is the provision of an improved quick release valve for quickly releasing the explosive gases from a combustion chamber to produce a seismic shock in which a valve seat block opens and closes the combustion chamber and an actuator moves the valve seat block to the open and close position and in turn is forced to the closed positioned by pressurized hydraulic fluid which when released allows the combustion gas pressure to actuate the actuator and open the valve seat block.

Another feature is the improvement in a quick release valve for a combustive seismic source having a valve seat block mounted for opening and closing the chamber with an actuator slidably and sealably engaging the seat block and exposed to pressure in the chamber acting to move the actuator to an open position with hydraulic pressure means connected to the actuator for moving the actuator and the seat block to a closed position with first and second engaging means between the actuator and the seat block for opening and closing the seat block, but with the engaging means being spaced with each other so that when the hydraulic pressure is released the seat block is opened with a snap action by the actuator.

A still further object of the present invention is the provision of a quick release valve using hydraulic fluid as a control fluid, but spacing the hydraulic control fluid from the combustion chamber thereby avoiding the high temperatures and contamination by the combustive gases.

Yet a further object of the present invention is the provision of a quick release valve wherein the sealing surfaces between the valve seat block with the chamber and with the actuator are metal to metal contact.

Yet still a further object of the present invention is the provision of improved ignition of the fuel/air mixture wherein the air is heated to a temperature of about 750F and introduced into the combustion chamber and fuel is thereafter sprayed therein and ignites spontaneously and eliminates the need for a spark or glow plug ignition source.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view, partly in cross section and partly schematic, illustrating the present invention wherein the combustion chamber is closed, and

FIG. 2 is a view similar to FIG. 1 showing the combustion chamber with the exhaust in the open position.

the apparatus of the present invention for producing a seismic shock wave in water and generally includes a combustion chamber 12, a quick. release valve 14 and control means 16 for controlling; the actuation of the 0 valve 14.

The combustion chamber 12 includes an air inlet 18 which receives compressed air from an air heater 20. Preferably, the incoming compressed air is heated to a temperature of approximately 750F. The combustion chamber 12 also includes a fuel inlet 22 for admitting a fuel, preferably a hydrocarbon fuel such as diesel oil, which is sprayed under pressure :into the chamber 12. Because of the elevated temperature of the air in the chamber I2, the metal parts of the chamber are also hot and the incoming pressurized fuel strikes the hot metal parts causing the fuel to ignite spontaneously to create pressurized gases to produce the seismic shock. Spontaneous ignition eliminates the need for a spark or glow plug ignition source thereby increasing the reliability of the ignition although ignition may be provided if desired. The chamber 12 includes an outlet 24 through which the combustion gases are released by the valve 14 to produce the desired seismic shock.

The valve 14 includes a valve seat block 26 having a valve surface 28 which seats on a valve seat 30 of the combustion chamber outlet 24, preferably which is a metal to metal seal for closing the combustion chamber, as shown in FIG. 1, when the valve seat block is moved against the chamber. The seat block 26 opens the chamber as best seen in FIG. 2, when the valve seat block 26 is moved off of the valve seat 30.

The releasing valve 14 includes an actuator 32 which is slidably supported, such as on a shaft 34 for movement in a first direction away from the chamber outlet 24 and for movement in a second direction toward the chamber outlet 24. The actuator 32 slidably supports the valve seat block 26 for moving the valve seat block 26 into the closed position (FIG. 1) or into the open position (FIG. 2). Gas pressure: in the combustion chamber 12 is prevented from leaking between the seat block 26 and the actuator 32 by suitable seals, preferably the metal seal rings 35 even when the actuator moves relative to the block 26. First engaging means such as a shoulder 36 on the actuator 32 and a shoulder 38 on the valve seat 26 (FIG. 1) are provided for en gagement when the actuator 32 moves in a direction away from the chamber outlet 24 for retracting the valve seat 26 away from the seat 30 on a combustion chamber outlet 24. Second engaging means such as a shoulder 40 on the actuator 32 and a shoulder 42 on the valve seat block 26 (FIG. 2) are provided for moving and holding the valve seat block 26 in the closed position when the actuator 32 is moved in the second direction or toward the chamber outlet 24 for closing the combustion chamber.

The actuator 32 includes a face 44 which is exposed to pressure in the combustion chamber 12, which pressure acts to move the actuator 32 in the first direction away from the chamber outlet 24. The valve seat block also includes a face 46, which when the valve block is in the closed position, as shown in FIG. 1, is exposed to the pressure in combustion chamber 12 and acts to seat the valve seat block 26 against the valve seat 30 for holding the valve seat block in the closed position until the seat 26 moves from seat 30. It is to be noted from FIG. 1 that pressure from the combustion chamber 12 acts on the face 46 of the seat block 26 even after the shoulder 40 on the actuator 32 begins its movement away from thecombustion chamber outlet 24 and the pressure on face seat block face 26 continues to hold the seat block 26 seated against seat 30 until the shoulder 36 on the actuator 32 engages shoulder 38 on the valve seat block 26 to retract the valve seat block 26.

The actuator 32 is moved in the second or closing position by a suitable hydraulic pressure means such as a hydraulic chamber 50 acting on a movable flange 52 against the fixedbase 54. Thus, increasing the hydraulic pressure in chamber 50 acts to overcome the force of the pressure in combustion chamber 12 acting on actuator face 44 tending to move the actuator 32 in the open direction thereby causing shoulder 40 on the actuator 32 to engage the shoulder 42 on the valve seat block 26 to seat the block on valve seat 30 and close chamber 12.

When it is desired to release the gas pressure in chamber 1, the hydraulic fluid in chamber 50 may be suitably released through supply line 56 by a suitable hydraulic pressure control means 16. It is also to be noted that the shoulders 36 and 40 on the actuator 32 are spaced from each other a distance whereby only one of them can be in engagement with the valve seat block 26 at a time. Thus, as the hydraulic pressure control means 16 is actuated to release the hydraulic fluid from chamber 50 and allow the actuator 32 to be accelerated in the first direction to open the valve the actuator 32 will build up speed so that at the time the shoulder 36 on the actuator 32 engages the shoulder '38 on the valve seat block 26 the valve seat block 26 is re tracted suddenly, providing a snap action or quick release of the valve 14. But it is to be particularly noted that the structure of the valve mechanism overcomes the compressible characteristics of the hydraulic fluid in chamber 50. That is, if the hydraulic fluid were used to directly hold the seat block 26 on the seat 30, the combusion pressure in the chamber 12 could compress the hydraulic fluid in the chamber 50 a small amount and open the seat 30. However, the use of block 26, separate actuator 32 and the lost motion between the actuator shoulders 36 and 40 allows the combustion pressure to compress the hydraulic fluid in the chamber 50 and move the actuator 32 a small amount without moving the seat block 26 since the seat block will remain seated by the force of pressure on face 46 until actuator shoulder 36 engages the block shoulder 38. Preferably, the weight of the actuator 32 is substantially greater than the weight of the valve seat block 26 thereby insuring a very quick opening of the valve 14 due to the larger mass and thus inertia of the actuator 32 as it strikes the valve seat block 26.

The hydraulic pressure control means 16 may include a two position three-way valve 58 which is shown in FIG. 1 as transmitting pressurized hydraulic fluid from a sump 60, through a pump 62, and through the line 56 into the chamber 50. The valve 58 is shown in FIG. 2 as being in the exhaust position whereby the fluid in line 56 flows from the hydraulic pressure chamber 50 and into the sump 60. If desired, the hydraulic pressure control means 16 may be automatically controlled for opening the quick release valve 14 at a desired time relative to combustion in the chamber 12 and the build up of the pressure in the chamber to a predetermined amount. For example, a pressure sensing means such as bellows 66 may be provided connected to and measuring the pressure in the chamber 12 and in turn controlling theactuation of an electrical switch 68 which is closed upon the actuation of a predetermined combustion pressure in the chamber 12 to furnish electrical power from an electrical source such as battery 70 to a solenoid valve 72. The valve 72 actu ates the two position valve 58 to release pressure from the hydraulic chamber 50. The actuator32 then moves away from the combustion chamber outlet 24 by the force of the pressure of the combustion gases in the chamber 12 acting against face 44 and in turn retracts the valve seat block 26 from the seat 30 to suddenly exhaust the explosive gases in the combustion chamber 12 to the surroundings. As the pressure in the combustion chamber 12 decreases, the bellows 66 will open the electrical switch 68 to release solenoid 72 to move the valve 58 into the position shown in FIG. 1 to again force pressurized hydraulic fluid into the chamber 50 and reseat the valve seat 26 for the next cycle. I

It is noted that the hydraulic chamber 50 is sealably enclosed by suitable seals 51 and 53 and that the chamber 50 is spaced from the combustion chamber 12 whereby the seals 51 and 53 are not contaminated by the combustion products or affected by the temperatures of the combustion chamber 12. Preferably, a chamber is provided separating the combustion chamber 12 and the hydraulic pressure chamber 50 and the chamber 80 includes outlet 82 to provide water cooling in the chamber 80. Chamber 50-may also include a piston 81 and a recess 83 into which the piston enters as shown in FIG. 2 in order to absorb the shock of the actuator 32 as it accelerates toward fixed end 54.- In addition, a vent 85 is provided to prevent any air pressure in the chamber 12 leaking down between the actuator 32 and the shaft 34 toward the hydraulic reservoir 50 from passing seal 53. As any air pressure approaches the vent 85, it will escape into the chamber 80 and pass through outlet 82.

In use, hot compressed air at a temperature of preferably 750F. is introduced into the air inlet 18 into the combustion chamber 12. At this point, the pressure in the combustion chamber is not sufficient to cause bellows 66 to actuate the electrical signal 68 and therefore the valve 58 is in the position shown in FIG. 1 whereby pressurized hydraulic fluid flows from the sump 60, by the action of the pump 62, into the line 56 and chamber 50 to move the actuator 32 towards the combustion chamber outlet 24. Movement of the actuator 32 moves the valve seat block 26 against the seat 30 closing the combustion chamber 12. Fuel is injected into the fuel inlet 22 and due to the elevated temperature of the air as well as the metal parts in the chamber 12 ignites spontaneously to provide the pressurized gases for creating a seismic shock. Upon rise of the pressure in the chamber 12 to a predetermined amount, which may be sensed by the bellows 66, the electrical switch 68 is closed, as best seen in FIG. 2, energizing the solenoid valve 72 to move the two-way valve 58 into a release position thereby exhausting hydraulic fluid from the chamber 50 through the line 56 and into the sump 60. The actuator 32 begins moving away from chamber 12 under the force of the high pressure gases in the chamber 12 and acquires a velocity such that when the shoulder 36 on the actuator 32 strikes the shoulder 38 on the valve seat block 26, the valve seat block 26 is retracted suddenly from the seat 30 and exhausts the high pressure gases to the surroundings. When the pressure in the chamber 12 decreases to a predetermined amount, the pressure sensing element 66 again opens the switch 68 to move the valve 58 to the position again shown in FIG. 1 to force hydraulic pressure back into the chamber 50 and repeat the cycle.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein.

What is claimed is:

1. In an apparatus for generating acoustic pulses in water having a combustion chamber and a fuel inlet and air supply inlet thereto for creating pressurized gases therein said combustion chamber having an outlet, the improvement in a valve for releasing the pressurized gases from the chamber comprising,

a valve seat block mounted for opening and closing said chamber outlet,

an actuator slidably and sealably engaging said seat block, said actuator exposed to pressure in the chamber acting to move the actuator in a first direction. hydraulic pressure means connected to the actuator for moving the actuator in a second direction,

first engaging means between the actuator and the seat block for moving the seat block in a said first direction,

second engaging means between the actuator and the seat block for moving the seat block in said second direction,

said first and second engaging means being spaced from each other whereby only one is in engagement at a time,

hydraulic pressure control means for controlling the hydraulic pressure against the actuator whereby when hydraulic pressure forces the actuator in said second direction the second engaging means causes the seat block to close said chamber, and when the hydraulic pressure is released pressure in the chamber forces the actuator in said first direction and the first engaging means causes the seat block to open the chamber with a snap action.

2. The apparatus of claim 1 wherein the weight of the actuator is greater than the weight of the valve block.

3. The apparatus of claim 1 including metal to metal seal means between the valve seat block and the chamber, and

metal to metal seal means between the valve seat block and the actuator.

4. The apparatus of claim 1 wherein said valve seat block when in a position closing said chamber includes a side exposed to the pressure in the chamber acting to move the valve block in said second direction.

5. The apparatus of claim 1 wherein said hydraulic pressure means is positioned spaced from the chamber for avoiding the heat of the chamber.

6. An apparatus for generating acoustic pulses in water comprising,

a combustion chamber for creating pressurized gases therein and having a fuel inlet and an air supply inlet, said chamber having an outlet,

an actuator slidable supported for movement in a first and second direction and having a face exposed to pressure in the chamber which acts to move the actuator in said first direction,

hydraulic pressure means connected to the actuator for moving the actuator in a second direction,

a valve seat block having a weight less than said actuator and slidably and sealably carried by the actuator to move in a second direction to close said chamber outlet and to move in a first direction to open said chamber outlet, said valve seat block when in position closing said chamber outlet includes a side exposed to the pressure in the chamber acting to seal the valve block against the outlet,

first shoulder means between the actuator and the seat block for moving the seat block in said first direction,

second shoulder means between the actuator and the seat block for moving the seat block in said second direction,

said first and second shoulder means being spaced from each other whereby only one can be engaged at a time,

hydraulic pressure control means for controlling the hydraulic pressure against the actuator whereby when hydraulic pressure forces the actuator in said second direction the second engaging means moves the seat block into the closed position against the chamber outlet, and when the hydraulic pressure is released pressure in the chamber forces the actuator in said first direction and the first shoulder means moves the seat block from the chamber with a snap action.

7. The apparatus of claim 6 including means for heating the air before upstream of the air supply inlet to approximately 750 F.

8. The apparatus of claim 6 including a water chamber separating the hydraulic pressure means from the combustion chamber.

I II! I! l 

1. In an apparatus for generating acoustic pulses in water having a combustion chamber and a fuel inlet and air supply inlet thereto for creating pressurized gases therein said combustion chamber having an outlet, the improvement in a valve for releasing the pressurized gases from the chamber comprising, a valve seat block mounted for opening and closing said chamber outlet, an actuator slidably and sealably engaging said seat block, said actuator exposed to pressure in the chamber acting to move the actuator in a first direction, hydraulic pressure means connected to the actuator for moving the actuator in a second direction, first engaging means between the actuator and the seat block for moving the seat block in a said first direction, second engaging means between the actuator and the seat block for moving the seat block in said second direction, said first and second engaging means being spaced from each other whereby only one is in engagement at a time, hydraulic pressure control means for controlling the hydraulic pressure against the actuator whereby when hydraulic pressure forces the actuator in said second direction the second engaging means causes the seat block to close said chamber, and when the hydraulic pressure is released pressure in the chamber forces the actuator in said first direction and the first engaging means causes the seat block to open the chamber with a snap action.
 2. The apparatus of claim 1 wherein the weight of the actuator is greater than the weight of the valve block.
 3. The apparatus of claim 1 including metal to metal seal means between the valve seat block and the chamber, and metal to metal seal means between the valve seat block and the actuator.
 4. The apparatus of claim 1 wherein said valve seat block when in a position closing said chamber includes a side exposed to the pressure in the chamber acting to move the valve block in said second direction.
 5. The apparatus of claim 1 wherein said hydraulic pressure means is positioned spaced from the chamber for avoiding the heat of the chamber.
 6. An apparatus for generating acoustic pulses in water comprising, a combustion chamber for creating pressurized gases therein and having a fuel inlet and an air supply inlet, said chamber having an outlet, an actuator slidable supported for movement in a first and second direction and having a face exposed to pressure in the chamber which acts to move the actuator in said first direction, hydraulic pressure means connected to the actuator for moving the actuator in a second direction, a valve seat block having a weight less than said actuator and slidably and sealably carried by the actuator to move in a second direction to close said chamber outlet and to move in a first direction to open said chamber outlet, said valve seat block when in position closing said chamber outlet includes a side exposed to the pressure in the chamber acting to seal the valve block against the outlet, first shoulder means between the actuator and the seat block for moving the seat block in said first direction, second shoulder means between the actuator and the seat block for moving the seat block in said second direction, said first and second shoulder means being spaced from each other whereby only one can be engaged at a time, hydraulic pressure control means for controlling the hydraulic pressure against the actuator whereby when hydraulic pressure forces the actuator in said second direction the second engaging means moves the seat block into the closed position against the chamber outlet, and when the hydraulic pressure is released pressure in the chamber forces the actuator in said first direction and the first shoulder means moves the seat block from the chamber with a snap action.
 7. The apparatus of claim 6 including means for heating the air before upstream of the air supply inlet to approximately 750* F.
 8. The apparatus of claim 6 including a water chamber separating the hydraulic pressure means from the combustion chamber. 